Install Docker

sudo apt-get install docker.io  // get from internet

Post-Install Setup

# Start Docker
sudo systemctl start docker

# Enable on boot - baar baar vm on krne pe automatic work krega
sudo systemctl enable docker

# Add user to docker group (no sudo needed)
sudo usermod -aG docker ubuntu

# Apply group change
newgrp docker

Verify Installation

docker --version
docker run hello-world

Notes

• docker.io = Ubuntu's packaged version (slightly older but works fine)
• For latest Docker CE, use the official Docker repo instead
• Run newgrp docker or re-login after adding user to group